[llvm] [Exegesis] Add supports to serialize/deserialize object files into benchmarks (PR #121993)

[Craig Topper via llvm-commits]

================
@@ -520,77 +565,94 @@ void benchmarkMain() {
     ExitWithError("cannot create benchmark runner");
   }
 
-  const auto Opcodes = getOpcodesOrDie(State);
-  std::vector<BenchmarkCode> Configurations;
-
-  unsigned LoopRegister =
-      State.getExegesisTarget().getDefaultLoopCounterRegister(
-          State.getTargetMachine().getTargetTriple());
-
-  if (Opcodes.empty()) {
-    Configurations = ExitOnErr(readSnippets(State, SnippetsFile));
-    for (const auto &Configuration : Configurations) {
-      if (ExecutionMode != BenchmarkRunner::ExecutionModeE::SubProcess &&
-          (Configuration.Key.MemoryMappings.size() != 0 ||
-           Configuration.Key.MemoryValues.size() != 0 ||
-           Configuration.Key.SnippetAddress != 0))
-        ExitWithError("Memory and snippet address annotations are only "
-                      "supported in subprocess "
-                      "execution mode");
-    }
-    LoopRegister = Configurations[0].Key.LoopRegister;
-  }
+  std::vector<BenchmarkRunner::RunnableConfiguration> RunnableConfigs;
+  SmallVector<unsigned> Repetitions;
 
-  SmallVector<std::unique_ptr<const SnippetRepetitor>, 2> Repetitors;
-  if (RepetitionMode != Benchmark::RepetitionModeE::AggregateMin)
-    Repetitors.emplace_back(
-        SnippetRepetitor::Create(RepetitionMode, State, LoopRegister));
-  else {
-    for (Benchmark::RepetitionModeE RepMode :
-         {Benchmark::RepetitionModeE::Duplicate,
-          Benchmark::RepetitionModeE::Loop})
-      Repetitors.emplace_back(
-          SnippetRepetitor::Create(RepMode, State, LoopRegister));
-  }
+  // Write to standard output if file is not set.
+  if (BenchmarkFile.empty())
+    BenchmarkFile = "-";
 
-  BitVector AllReservedRegs;
-  for (const std::unique_ptr<const SnippetRepetitor> &Repetitor : Repetitors)
-    AllReservedRegs |= Repetitor->getReservedRegs();
-
-  if (!Opcodes.empty()) {
-    for (const unsigned Opcode : Opcodes) {
-      // Ignore instructions without a sched class if
-      // -ignore-invalid-sched-class is passed.
-      if (IgnoreInvalidSchedClass &&
-          State.getInstrInfo().get(Opcode).getSchedClass() == 0) {
-        errs() << State.getInstrInfo().getName(Opcode)
-               << ": ignoring instruction without sched class\n";
-        continue;
+  if (!RunMeasurement.empty()) {
+    // Right now we only support resuming before the measurement phase.
+    auto ErrOrBuffer =
+        MemoryBuffer::getFileOrSTDIN(RunMeasurement, /*IsText=*/true);
+    if (!ErrOrBuffer)
+      report_fatal_error(errorCodeToError(ErrOrBuffer.getError()));
+
+    std::vector<Benchmark> Benchmarks =
+        ExitOnErr(Benchmark::readYamls(State, **ErrOrBuffer));
+    deserializeRunnableConfigurations(Benchmarks, *Runner, RunnableConfigs,
+                                      Repetitions);
+  } else {
+    const auto Opcodes = getOpcodesOrDie(State);
+    std::vector<BenchmarkCode> Configurations;
+
+    unsigned LoopRegister =
+        State.getExegesisTarget().getDefaultLoopCounterRegister(
+            State.getTargetMachine().getTargetTriple());
+
+    if (Opcodes.empty()) {
+      Configurations = ExitOnErr(readSnippets(State, SnippetsFile));
+      for (const auto &Configuration : Configurations) {
+        if (ExecutionMode != BenchmarkRunner::ExecutionModeE::SubProcess &&
+            (Configuration.Key.MemoryMappings.size() != 0 ||
----------------
topperc wrote:

!empty()?

https://github.com/llvm/llvm-project/pull/121993